Soil science students are required to apply knowledge from a range of disciplines to unfamiliar scenarios to solve complex problems. To encourage deep learning (with student performance an indicator of learning), a formative assessment exercise was introduced to a second-year soil science subject. For the formative assessment exercise, students were required to prepare a draft of a critical review of a current topic in soil science, and then (following guidance from staff members) provide feedback to each other through a peer assessment exercise. In contrast to expectations, the formative assessment did not appear to improve overall student performance in this task based upon their grades for this task. Furthermore, despite being given an exemplar and attending a workshop where tactics for searching the scientific literature were discussed, this did not increase the likelihood that students would cite studies from the scientific literature when conducting their critical review. Regardless of these observations, the students were positive and appreciated the feedback they received through the exercise. This study demonstrates the need to ensure that feedback is effective and enables students to identify their weaknesses and modify their work accordingly. (Contains 4 tables.)